Feedback on False Positives from Drug Testing, page 41

False Positives Forum

This forum is intended to help those who Do NOT Abuse Drugs. We do NOT support the illegal use of any substance. If you have experience with false positives, share your experience. What would you tell someone about drug testing and false positives? Please remember that we do not give medical or legal advice.

Subj: Liquid hydrocodone
Date: 7/21/2008
I’ve had a couple of urine drug tests and for what ever reason, liquid hydrocodone has shown up. I do not take any liquid hydrocodone. The only thing other then my prescription meds, is over the counter liquid NiQuil every once in awhile. I also take Benadryl w/Ibuprophen. Again, these are aside from reg. precriptions. What can cause the liquid hydrocodone to show?


AskDocWeb: There was one other report from someone who received a false positive for hydrocodone while taking Ibuprofen but we haven’t been able to find a professional reference for that. Benadryl (Diphenhydramine) has been reported to show up as false positives for Benzodiazepines, PCP, and Tricyclic Antidepressants 2-4 days after a single use. (Reference 45).

Subj: Urine tested positive for cocaine
Date: 7/22/2008
I had a urine test done at Lifestream yesterday and they said I tested positive for cocaine. I have never used cocaine. My Dr has me on adderall 30 MG, Seroquel 200 MG, and Welbutrn 150 MG. Could these drugs in a urine test make them think I was using cocaine? Is there a test I can take that is just for cocaine so I can prove to them I don’t use cocaine. I am 16 years old and live with my grandparents. I don’t want to go to jail for something I didn’t do. Please give me some advice. Thank you,


AskDocWeb: Some urine tests have a problem with both adderall and wellbutrin. The test you want is called a Gas Chromatograph/Mass Spectrometer (GC/MS) confirmation test. If you can find out what the name of the urine test is or who manufactures it, you can go to their website to find out what products show up as a false positive on their tests.

Subj: Tested positive for THC
Date: 7/23/2008
I just tested positive for THC. I have not used marijuana in several years. I am a heart patient and I take the prescription medications Lisinopril, Simvastatin, Atenolol, and Niaspan daily. In addition, I take Aspirin, Omeprazole, and Red Yeast Rice suppliments daily and occasionally Aleve for pain relief. Could this combination of medications produce a “false positive” result from a drug screening?


AskDocWeb: The only drug you mention that is on our list is Aleve.

Subj: Positive for PCP
Date: 7/23/2008
I was positive at the probation office for PCP and I have never used it in my life. I have been clean for over a year and I have been on a methadone clinic for 4 years now & am doing very well. I bought 2 home drug test kits and they also tested positive for PCP a week after seeing my P.O. I am expected to give a 2nd urine test to prove my innocents and how am going to do that when this is showing in my urine when I am NOT consuming anything except methadone, excedrin, vivarin (caffeine pills over the counter), and ibuprophen, and vitamins. I was taking an over the counter sleep med. last week but that simply has the ingredient that benadryl contains. I took some night time cold meds about 2 weeks ago or more I thought maybe that was causing this false PCP result but that was over 2 weeks ago that should have been out of my system by now. I am facing 4 years in a state prison if this test shows positive yet again. PLEASE HELP ME!!!


The only drugs that have been reported to falsely show up as PCP are Benadryl, Diazepam, Diphenhydramine, Effexor Tablets (venlafaxine hydrochloride) and Ketamine.

Subj: What medications cause a false positive?
Date: 7/23/2008
I failed the methamphetamines portion of a drug test what medicadions can cause a false positive and can prozac do it???


AskDocWeb: Here is a list of medications that may show up as a false positive. Prozac is not on the list.

Subj: Antibuse
Date: 7/28/2008
I recently took a UA for alcohol, and had a positive reading. I have not had any alcohol in my system for several months. I do take the prescreption Antibuse. Could this cause a positive reading?


AskDocWeb: Sorry Michael, we’ve not heard of that happening.

Subj: Lyrica or Mirapex?
Date: 7/29/2008
Can Lyrica or Mirapex give a false positive for benzodiazepines.


AskDocWeb: No.

Subj: Crantex (phenylephrine) oxaprozin
Date: 7/29/2008
I have just tested positive for benzo. The only drugs I have taken were crantex(phenylephrine), oxaprozin and one a day weight loss vitamins. Could any of these turn up as a false positive?


AskDocWeb: Yes, oxaprozin may show up as a false positive for Benzodiazepines on a urine drug test.

Subj: References
Date: 7/29/2008
Love the website. We are fighting to adopt our Grandson and are using your False Positives article. Just have a question as to where to look up the References. Can’t find it anywhere and it would be very helpful. Thanks,


AskDocWeb: Yes, you can find the references here.

Subj: Tylenol with Codeine?
Date: 7/30/2008
Can a person test positive for cocaine by taking Tylenol with Codeine?


AskDocWeb: According to a Toxicology Lab Technical Brief it appears that may be possible.

Subj: Positive urine test for cocaine
Date: 7/30/2008
My daughter is an alcoholic and had a court date recently. She knew she would be getting a test done. Her test results were fine for alcohol, but she tested positive for cocaine. She vehemently denies having used coke and for a great many reasons, I believe her in this case. However, she had broken her foot not long ago and was prescribed tylenol with codeine. I have done much research on this and it seems there are many answers – no, tylenol with codeine would not result in a false positive, or yes, codeine is an opiate and that would result in a false positive and even that tylenol would result in a false positive. I am unsure what the right answer is. Do you feel that it is possible that tylenol with codeine would result in a positive urine test for cocaine?


AskDocWeb: Yes, it is the codeine that causes the problem. Codeine (and other narcotic drugs) is obtained from opium.

Subj: Lactulose or enemas?
Date: 7/31/2008
I have tested positive for opiates. I have not taken any opiates. I do however take lactulose on an as needed basis and also use enimas when needed. Could this give me a false positive for opiates??


AskDocWeb: We haven’t seen anything to indicate that either would cause a false positive.

Subj: Percocet
Date: 7/31/2008
I am trying to help someone who tested positive for cocaine. I know for a fact the GC/MS was used. The person has a prescription for percocet and insists the result is a false positive due to the percocet. Does the GC/MS automatically rule out false positives for cocaine due to percocet use? What if the lab was not aware the person was using percocet? If the lab also tested for opiates, wouldn’t he also test positive for that?


AskDocWeb: If the lab was not aware that the person was using percocet that would likely cause a problem because percocet will test positive for opiates and it is not a false positive.

Subj: Hair follicle drug test
Date: 8/1/2008
I have taken a hair follicle drug test that has come back positive for cocaine. I have not done this drug. What would cause this to be?


AskDocWeb: We know that it can be absorbed through the skin. Is it possible that you were in contact with someone who did use cocaine?

Subj: Zoloft
Date: 8/2/2008
I participate in random drug screening for my job as a registered nurse. I started taking Zoloft 1 week ago, and yesterday had my first false positive for Benzodiazepenes. I am convinced that Zoloft is the offending substance, since it is the only new medication that I take.


Date: 8/2/2008
What over the counter allergy cough serpress meds might cause false pos benzodiazepines test?


AskDocWeb: Allerest has been reported to sometimes show up as a false positive for Meth (See references 1, 2, 3, 7, 11, 16, and 18) but no over-the-counter product has been reported to cause a false positive for benzodiazepines.

Subj: Positive for cocaine
Date: 8/3/2008
I have had a urine and hair follicure test to come back positive for cocaine, I have not used in 2 years. I have taken lots of ephedra, and drixoral. Also, drink lots of tonic water and a herbal tea that has coca extract in it? Will this show false/positive? Apparently so.


AskDocWeb: We haven’t found a reference for any of those causing a false positive for cocaine. That is not saying that it couldn’t happen, just that there is no evidence of it.

Subj: Benzodiazepines?
Date: 8/5/2008
My daughter has been in an out-patient rehab for the past 3 months (for heroin). She has been doing very well as this was her choice to go this time. She has had consistently clean U.A.’s and tonight she had a dirty one for benzodiazapines. She has had a sinus infection and the doctor put her on Septra and Erythromycin. She also takes suboxone. She also has been using a saline nose spray called Simply Saline. Could the antibiotics or Saline spray have caused a false positive?


AskDocWeb: No, antibiotics have been reported to show up as false positives for heroin and cocaine but not benzodiazepines. And the saline spay would not cause a false positive.

Subj: Percocet
Date: 8/5/2008
I have a script for loratab, but I forgot my medicine at home and was hurting really bad so my grandpa gave me a percocet. If my doctor tests me, will that show up different or the same?


AskDocWeb: Percocet will test positive for opiates and that is not a false positive.

Subj: Smoked marijuana
Date: 8/6/2008
After having smoked marijuana for the first time in..A LONG was approx 3 weeks and I was drug tested. I explained to the doc what I knew the results would be..she understood, and explained because I take drug tests for my pain medication, I will have to continue drug tests. My fear is that due to me having to take phenegran *promethazine* for the nausea, hydrocodone and klonopin, somethings going to come back and not look good to them. As I was reading, it can make a false positive for THC while taking promethazine… Is it even fair if I get wrongly accused at the next test? They know I take these prescribed medications, but I dont want now because I had an ‘oops’ for them not to believe me if I bring this up about the promethazine…I think they’ll think I’m trying to get out of something…which I’m not. I struggle from endometriosis–gone through complete hell if I may say…and this depends on me being able to be cared for by them anymore because I needed 2 vicodin a day early. So they drug tested me. I guess my “question” is further helped by the above information. If something was to come back, how can I bring this up to my doctor, without her accusing me of trying to find a ‘fake answer’? I’m just concerned…and NOT a drug user.


AskDocWeb: It is difficult to take you seriously when you start out with an admission of drug use and then end with a denial.

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